I don't necessarily agree with this. We have no idea how long JM hair was during the time MH was murdered. Remember, the sketch it what the 2005 rape suspect looked like. Also, I did a quick google search of 6 months dreadlocks growth and images of men with similar hair length popped up. It's easier to retain length when locking hair. JMO
We don't know how long his hair was in the fall of 2009 when MH was murdered, no. But various posts on this forum have mentioned that friends of JM supposedly commented that he started to "grow the dreds" after MH was murdered (as a way to disguise his appearance). I was responding to that theory/surmise.
Could someone with long hair "lock it" into dreads of similar length? Of course, yes . . . but has anyone at any time seen images or reports of JM with long hair, un-dredded? Like, say, an Afro? No. All the pre-dred images show close-cropped hair. It would be really memorable and remarked upon, I think, if he had long hair, between 2005 and 2009.
And there really is no way he could grow out close-cropped short hair to dreds of that length, 3" to 5" inches, in six months' time. Human hair grows at a rate of a half inch per month, approximately. But with black hair there's shrinkage. Put it this way, my daughter's hair, if you pull it straight, is actually about 15" inches long; but not pulled straight, just left natural, it only falls about 7" inches -- because it's like a spring/coil. So JM's 3" to 5" inches of dred represent more than 3" to 5" inches of real growth. Say, 6" or 7" inches of actual growth . . . and that would take a year or so, I believe.
Could he have had a weave put in, for fake dreds, as the O.P. above suggests? Sure. I myself have never heard of a weave or extensions that short. His hair in the April 2010 pix (supposedly from April 2010, anyway) look very much like natural hair being locked and grown out to me. Just IMHO. . . . Personally, I think maybe the photos are from April 2011, and the witness is mistaken about 2010; or, I think he started growing his short hair out into dreds before the MH murder, not after.
PS: His dreds in recent photos look very pristine, and more like extensions or weave than the April 2010 short dreds do, I think.